Alternative front-ends like nitter.net still seem to work, so that might be interesting to know if you're running into the same thing.
See also this discussion from when they did a similar thing 2 years ago: https://news.ycombinator.com/item?id=28289263
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or are completely gone from the stream
Here you have different front-ends for propietary services.
Replace "twitter.com" with "nitter.esmailelbob.xyz" for every URL.
For convenience, you can try Libredirect for Firefox, and IceRaven from FDroid as a Firefox alternative for Android.